A chemical status predictor. A methodology based on World-Wide sediment samples

Area of Science:

• Environmental Chemistry
• Water Quality Assessment
• Geochemistry

Background:

• Global water body chemical quality assessment is hindered by resource limitations and lack of interest.
• The European Water Framework Directive (WFD) sets standards for good chemical status.
• Assessing natural background concentrations is crucial for evaluating anthropogenic impacts.

Purpose of the Study:

• To develop a rapid methodology for identifying water bodies not meeting WFD chemical status requirements.
• To establish a simple criterion for estimating natural background concentration levels.
• To provide a tool for preliminary screening of water quality.

Main Methods:

• Calculation of World-Wide Natural Background Levels (WWNBLs) and World-Wide Threshold Values (WWTVs).
• Indexes based on the concentration of seven key elements (As, Cd, Cr, Cu, Ni, Pb, Zn) in sediments.
• Selection of elements based on UNEP and USEPA recommendations for environmental toxicity concerns.

Main Results:

• Methodology applied to 134 sediment samples from 11 transitional water bodies across 7 countries.
• Six water bodies met the WFD good chemical status criteria.
• The remaining water bodies exceeded WWTVs for at least one element, indicating potential pollution.

Conclusions:

• The proposed methodology offers a fast and effective first approach for water quality screening.
• It aids in identifying areas exceeding natural background levels for toxic elements.
• The study highlights the need for continued monitoring and management of transitional water bodies worldwide.